A012569 - OEIS

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A012569

sec(sinh(x)*cos(x))=1+1/2!*x^2-3/4!*x^4-123/6!*x^6-455/8!*x^8...

1, 1, -3, -123, -455, 162889, 7941813, -647037363, -141890950799, 176381997457, 4580546025413229, 624311846901265941, -219756895048343473751, -104610854473143576793127

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,3

LINKS

Table of n, a(n) for n=0..13.

MATHEMATICA

With[{nn=30}, Take[CoefficientList[Series[Sec[Sinh[x]Cos[x]], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Dec 29 2021 *)

CROSSREFS

Sequence in context: A229633 A171357 A209363 * A078258 A258658 A222186

Adjacent sequences: A012566 A012567 A012568 * A012570 A012571 A012572

KEYWORD

sign

AUTHOR

Patrick Demichel (patrick.demichel(AT)hp.com)

STATUS

approved